Title :
A 3D large signal model for helix TWT
Author :
David, Jean-Francois ; Bariou, D.
Author_Institution :
Thales Electron Devices, Velizy, France
Abstract :
In a helix traveling wave tube, the interaction between the electron beam and the backward wave can lead to instabilities as BWO (backward wave oscillation) if the beam current is large enough. As the efficient part of the circuit fields varies in the angular direction, a 3D tool is needed to model such a phenomena. The numerical model is presented, with some examples of BWO starting conditions research. Close to the π mode, both forward and backward interact with the beam and any coupling of both waves has a strong effect. Consequently the threshold current is lowered. Several causes of coupling have been studied.
Keywords :
backward wave oscillators; travelling wave tubes; π mode; 3D large signal model; 3D tool; BWO; backward wave oscillation; helix TWT; helix traveling wave tube; numerical model; threshold current; Computational modeling; Couplings; Electron tubes; Harmonic analysis; Integrated circuit modeling; Oscillators; Solid modeling; π mode oscillation; 3D modeling software; BW oscillation; Helix TWT (Traveling Wave Tube);
Conference_Titel :
Vacuum Electronics Conference (IVEC), 2013 IEEE 14th International
Conference_Location :
Paris
Print_ISBN :
978-1-4673-5976-4
DOI :
10.1109/IVEC.2013.6571135
